Northumbria was an early medieval Anglo-Saxon kingdom in what is now Northern England and south-east Scotland.
Pope Eleutherius, also known as Eleutherus, was the bishop of Rome from c. 174 to his death. His pontificate is alternatively dated to 171-185 or 177-193. He is venerated as a saint in the Catholic Church.
The Battle of Badon, also known as the Battle of Mons Badonicus, was purportedly fought between Britons and Anglo-Saxons in Post-Roman Britain during the late 5th or early 6th century. It was credited as a major victory for the Britons, stopping the westward encroachment of the Anglo-Saxon kingdoms for a period.
Caer is a placename element in Welsh meaning "stronghold", "fortress", or "citadel", roughly equivalent to an Old English suffix (-ceaster) now variously written as -caster, -cester, and -chester.
Vortigern, also spelled Vortiger, Vortigan, Voertigern and Vortigen, was a 5th-century warlord in Britain, known perhaps as a king of the Britons or at least connoted as such in the writings of Bede and Gildas. His existence is contested by scholars and information about him is obscure.
The History of the Britons is a purported history of early Britain written around 828 that survives in numerous recensions from after the 11th century. The Historia Brittonum is commonly attributed to Nennius, as some recensions have a preface written in that name. Some experts have dismissed the Nennian preface as a late forgery and argued that the work was actually an anonymous compilation.
Nennius – or Nemnius or Nemnivus – was a Welsh monk of the 9th century. He has traditionally been attributed with the authorship of the Historia Brittonum, based on the prologue affixed to that work. This attribution is widely considered a secondary (10th-century) tradition.
The Battle of Dun Nechtain or Battle of Nechtansmere was fought between the Picts, led by King Bridei Mac Bili, and the Northumbrians, led by King Ecgfrith, on 20 May 685.
The Matter of Britain is the body of medieval literature and legendary material associated with Great Britain and Brittany and the legendary kings and heroes associated with it, particularly King Arthur. The 12th-century Welsh cleric Geoffrey of Monmouth's Historia Regum Britanniae, widely popular in its day, is a central component of the Matter of Britain.
Partholón is a character in medieval Irish Christian pseudo-history, who is said to have led one of the first groups to settle in Ireland. 'Partholón' comes from the Biblical name Bartholomaeus (Bartholomew), and may be borrowed from a character who appears in the Christian pseudo-histories of Saints Jerome and Isidore of Seville.
Cassivellaunus was a historical British military leader who led the defence against Julius Caesar's second expedition to Britain in 54 BC. He led an alliance of tribes against Roman forces, but eventually surrendered after his location was revealed to Julius Caesar by defeated Britons.
The Trojan genealogy of Nennius was written in the Historia Brittonum of Nennius and was created to merge Greek mythology with Christian themes. As a description of the genealogical line of Aeneas of Troy, Brutus of Britain, and Romulus and Remus, the founders of Rome, it is an example of the foundation genealogies found not only in early Irish, Welsh and Saxon texts but also in Roman sources.
Nennius is a mythical prince of Britain at the time of Julius Caesar's invasions of Britain. His story appears in Geoffrey of Monmouth's History of the Kings of Britain (1136), a work whose contents are now considered largely fictional. In Middle Welsh versions of Geoffrey's Historia he was called Nynniaw.
Vortimer, also known as Saint Vortimer, is a figure in British tradition, a son of the 5th-century Britonnic ruler Vortigern. He is remembered for his fierce opposition to his father's Saxon allies. In Geoffrey of Monmouth's Historia Regum Britanniae, he overthrows his father and reigns as King of Britain for a brief period before his death restores Vortigern to power.
The Treason of the Long Knives is an account of a massacre of British Celtic chieftains by Anglo-Saxon soldiers at a peace conference on Salisbury Plain in the 5th century. The story is thought to be pseudohistorical as the only surviving records mentioning it are centuries later in the semi-mythological histories of the Historia Brittonum and the Historia Regum Britanniae. Though a popular cautionary tale in medieval Europe, there is no other historical evidence for The Treason of the Long Knives. Most historians interpret the story as a purely literary construction.
Segontium is a Roman fort on the outskirts of Caernarfon in Gwynedd, North Wales.
Elfodd, Elvodug or Elfoddw was a Welsh bishop. He induced the Welsh church to accept the Roman computus for determining the date of Easter endorsed elsewhere in Britain at the Synod of Whitby in 664. This was after centuries of continuing the practice.
The Battle of Guoloph, also known as the Battle of Wallop, took place in the 5th century. Various dates have been put forward: 440 AD by Alfred Anscombe, 437 AD according to John Morris, and 458 by Nikolai Tolstoy. It took place at what is now Nether Wallop, 15 kilometers southeast of Amesbury, in the district of Test Valley, northeastern Hampshire. The battle was an internal conflict between the rival Britonnic forces of Ambrosius Aurelianus and Vortigern (Vitalinus).
Deruvian, also known by several other names including Damian, was a possibly legendary 2nd-century bishop and saint, said to have been sent by the pope to answer King Lucius's request for baptism and conversion to Christianity. Together with his companion St Fagan, he was sometimes reckoned as the apostle of Britain. King Lucius's letter may represent earlier traditions but does not appear in surviving sources before the 6th century; the names of the bishops sent to him does not appear in sources older than the early 12th century, when their story was used to support the independence of the bishops of St Davids in Wales and the antiquity of the Glastonbury Abbey in England. The story became widely known following its appearance in Geoffrey of Monmouth's History of the Kings of Britain. This was influential for centuries and its account of SS Fagan and Deruvian was used during the English Reformation to support the claims of both the Catholics and Protestants. Christianity was well-established in Roman Britain by the third century. Some scholars therefore argue the stories preserve a more modest account of the conversion of a Romano-British chieftain, possibly by Roman emissaries by these names.
Lebor Bretnach, formerly spelled Leabhar Breathnach and sometimes known as the Irish Nennius, is an 11th-century historical work in Gaelic, largely consisting of a translation of the Historia Brittonum. It may have originated in Scotland, although it has traditionally been attributed to the Irish poet Gilla Cóemáin.
